In electrical switches which contain a vacuum interrupter as the actual switching element, a drive linkage is provided for moving the switching contact piece which can be moved and is electrically connected to the exterior via a current supply bolt, which drive linkage acts on the moveable switching contact piece via a contact compression spring during the connection process and, during disconnection—after traveling through a certain acceleration distance—drives the moving switching contact piece suddenly. In order to stabilize the intrinsic high disconnection rating of such vacuum interrupters or such vacuum interrupters which are provided with radial field or axial field contact pieces, it is known for the moveable switching contact piece to be influenced directly after contact disconnection such that the contact gap is opened by at least 1 mm after at the latest 1.3 ms, that is to say for the moveable switching contact piece to be given a high initial acceleration. In the case of radial field contact pieces, it has been found to be advantageous for a contact piece disconnection speed of 2 m/s to be achieved after 0.8 ms. With this known influence on the time sequence of the opening of the contact gap, the disconnection speed of the moveable switching contact piece is essentially constant over the entire contact travel, apart from the phase of the high initial acceleration and the severe braking on reaching the full contact travel (DE 38 15 805 C2).
Furthermore, a high-voltage vacuum switch is known, in which the contact travel is subdivided by means of a special design configuration of the vacuum interrupter into three sections which are referred to as “functional stages” (the switching travel, a first stage of the isolating travel and a second stage of the isolating travel). The special design configuration comprises the association of in each case one potential ring with each contact piece and an axially moveable arrangement of the housing of the vacuum interrupter with respect to the stationary switching contact piece. These measures mean that the two switching contact pieces are located in the field shadow of the respective potential ring when the moving switching contact is in the off position, thus improving the isolation capability of the vacuum interrupter for a given contact separation (DE 195 19 078 A1).